To meet a peak data rate requirement of the International Telecommunication Union for fourth-generation communications technologies, a CA (carrier aggregation) technology is introduced to an LTE-A (Long Term Evolution-Advanced) system. In addition, in order to support technologies such as downlink MIMO (multiple input multiple output) transmission and hybrid automatic repeat, a terminal needs to feed UCI (uplink control information) back to a base station. The UCI includes CSI (channel state information), HARQ (hybrid automatic repeat request), and like information.
In the prior art, when feeding UCI back to a base station, if a terminal simultaneously accesses multiple downlink member carriers to receive downlink data, the terminal needs to feed back, in an uplink direction, CSI of each downlink member carrier with respect to each downlink member carrier, and HARQ information of each downlink member carrier with respect to data scheduled on each downlink member carrier.
The base station semi-statically configures, through high layer signaling and for periodic CSI of each carrier, a reporting mode, a reporting cycle and a subframe offset. A user equipment determines, according to the reporting mode indicated in the high layer signaling, a reporting type corresponding to CSI to be reported, and determines, according to the reporting cycle and the subframe offset indicated in the high layer signaling, a reporting moment of the CSI of each reporting type. The user equipment, if detecting a physical downlink control channel PDSCH (physical downlink shared channel) transmission or a PDCCH (physical downlink control channel) used to indicate release of semi-persistent scheduling, needs to feed back an HARQ-ACK (acknowledgment). Therefore, in an LTE-A carrier aggregation scenario, the channel state information and the hybrid automatic repeat acknowledgment information need to be reported on one uplink subframe at the same time, where the channel state information to be reported may correspond to one or more downlink carriers and the hybrid automatic repeat acknowledgment information to be reported may also correspond to one or more downlink carriers. In a carrier aggregation scenario, how simultaneous transmission of the periodic CSI and the hybrid automatic repeat acknowledgment information can be supported is an issue to be solved.